Crystal-Structures of 2 3-Substituted 10,11-Dimethoxy-1,2,3,4,5,6-Hexahydro-7,9-etheno-3-benzazecine Derivatives

Abstract

The title compounds are 3-aza[6](1,7)-naphthalenophanes with 3-Me and 3-CO₂Me substituents, C₁₈H₂₃NO₂ and C₁₉H₂₃NO₄; in the former the chemical shift of the naphthalene hydrogen enclosed by the medium nitrogen-containing ring is the highest yet observed in a derivative of this type ( σ 9.33). In order to examine the environment of this hydrogen atom and the expected associated naphthalene ring distortions in both compounds, single-crystal X-ray structure determinations have been carried out at 295 K showing the transannular H…N distance in the methyl derivative to be remarkably short at 2.08(2) Å . Crystals are triclinic, P1, a 11.683(3), b 10.846(3), c 6.729(2) Å, α 90.08(2), β 93.33(2), γ 112.88 Z 2; R was 0.041 for 1378 'observed' reflections. Crystals of the 3-CO₂Me derivative are also triclinic, P1, a 12.587(9), b 10.650(4), c 6.758(3) Å , a 91.91(3), β 100.51(4), γ 104.74(5)° Z 2; R 0.067 for 1267 'observed' reflections.